Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4572351 | CATENA | 2008 | 11 Pages |
Abstract
Prescribed fire is a technique sometimes used in forest management but the effects on soil are not fully understood. Soil is a complex system and the spatial variability of properties and processes may increase after a disturbance like fire. We modelled three soil cations Ca2+, Mg2+ and K+ with probabilistic methods and geostatistics in order to assess the spatial effects of a prescribed fire within a plot (108Â m2). Soil samples were collected during 6 different sampling campaigns (pre fire, post fire, 2Â months, 5Â months, 1Â year, and 3Â years after the prescribed fire). The sampling interval was designed to detect the effect of rainfall (1315Â mm for the 3Â years with 72Â mm/h peak intensity) on the spatial soil changes as consequence of processes such as: leaching, soil erosion, etc. We developed an index of response to compare each cation after the prescribed fire with its pre-fire levels. Results showed that calcium and magnesium recover with time to their original concentrations. Potassium increase slightly in half of the plot just after fire; however, three years after fire the concentration was two orders of magnitude lower than the pre-fire state. The divalent cations (Ca2+ and Mg2+) were more homogeneous but the monovalent cation (K+) was more heterogeneous after the fire. Furthermore the maximum rainfall period triggered different spatial processes and the type of process was a function of the valence of the cation.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Earth-Surface Processes
Authors
LuÃs Outeiro, Francesc Asperó, Xavier Ãbeda,